package com.chilli.cosima.utils;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;

public class RandomNumUtil
{
    private ByteArrayInputStream image;//图像   
    
    private String str = "";//验证码   
    
    private RandomNumUtil()
    {
        init();//初始化属性   
    }
    
    /*  
     * 取得RandomNumUtil实例  
     */
    public static RandomNumUtil Instance()
    {
        return new RandomNumUtil();
    }
    
    /*  
     * 取得验证码图片  
     */
    public ByteArrayInputStream getImage()
    {
        return this.image;
    }
    
    /*  
     * 取得图片的验证码  
     */
    public String getString()
    {
        return this.str;
    }
    
    private void init()
    {
        //       在内存中创建图象   
        int width = 65, height = 20;
        BufferedImage image = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);
        //       获取图形上下文   
        Graphics g = image.getGraphics();
        //      生成随机类   
        Random random = new Random();
        //       设定背景色   
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        //      设定字体   
        g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
        //       随机产生155条干扰线，使图象中的认证码不易被其它程序探测到   
        g.setColor(getRandColor(160, 200));
        for (int i = 0; i < 155; i++)
        {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }
        //       取随机产生的认证码(4位数字)   
        String sRand = "";
        for (int i = 0; i < 4; i++)
        {
            String rand = String.valueOf(random.nextInt(10));
            sRand += rand;
            // 将认证码显示到图象中   
            g.setColor(new Color(20 + random.nextInt(110),
                    20 + random.nextInt(110), 20 + random.nextInt(110)));
            //      调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成   
            g.drawString(rand, 13 * i + 6, 16);
            this.str += rand;/*   赋值验证码   */
        }
        //       图象生效   
        g.dispose();
        ByteArrayInputStream input = null;
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        try
        {
            ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);
            ImageIO.write(image, "JPEG", imageOut);
            imageOut.close();
            input = new ByteArrayInputStream(output.toByteArray());
        }
        catch (Exception e)
        {
            System.out.println("验证码图片产生出现错误：" + e.toString());
        }
        
        this.image = input;/*  赋值图像  */
    }
    
    /*  
     * 给定范围获得随机颜色  
     */
    private Color getRandColor(int fc, int bc)
    {
        Random random = new Random();
        if (fc > 255)
            fc = 255;
        if (bc > 255)
            bc = 255;
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }
    
}
